Toolshed (#17895)

* ogh

* i should save my work

* ogh

* hhcdfhjbghshbxdfhghshc
- lots of bugs in parsing still
- invocation is a stub

* expr parsing works

* awawa

* Saving work

* Improve APIs a bit all around, add shortcuts.

* awa

* awa

* AAAAAA

* save work

* Move shit to engine

* lord

* bql is kill

* forgot the fucking bike rack

* bql is kill for real

* pjb will kill me

* aughfhbdj

* adgddf

* gdsgvfvxshngfgh

* b

* hfsjhghj

* a

* tf you mean i have to document it

* follow C# standards

* Assorted cleanup and documentation pass, minor bugfix in ValueRefParser.

* Start porting old commands, remove that pesky prefix in favor of integrating with the shell.

* bw

* Fix valueref up a bit, improve autocomplete for it.

* awa

* fix tests

* git shut up

* Arithmetic commands.

* parse improvements

* Update engine.

---------

Co-authored-by: moonheart08 <moonheart08@users.noreply.github.com>

Content.Server/NewCon/Commands/AdminDebug/ACmdCommand.cs

@@ -0,0 +1,34 @@
+using Content.Server.Administration;
+using Content.Server.Administration.Managers;
+using Content.Shared.Administration;
+using Robust.Server.Player;
+using Robust.Shared.Toolshed;
+using Robust.Shared.Toolshed.Syntax;
+
+namespace Content.Server.NewCon.Commands.AdminDebug;
+
+[ToolshedCommand, AdminCommand(AdminFlags.Debug)]
+public sealed class ACmdCommand : ToolshedCommand
+{
+    [Dependency] private readonly IAdminManager _adminManager = default!;
+
+    [CommandImplementation("perms")]
+    public AdminFlags[]? Perms([PipedArgument] CommandSpec command)
+    {
+        var res = _adminManager.TryGetCommandFlags(command, out var flags);
+        if (res)
+            flags ??= Array.Empty<AdminFlags>();
+        return flags;
+    }
+
+    [CommandImplementation("caninvoke")]
+    public bool CanInvoke(
+        [CommandInvocationContext] IInvocationContext ctx,
+        [PipedArgument] CommandSpec command,
+        [CommandArgument] ValueRef<IPlayerSession> player
+        )
+    {
+        // Deliberately discard the error.
+        return ((IPermissionController) _adminManager).CheckInvokable(command, player.Evaluate(ctx), out var err);
+    }
+}